Is it cheaper to cook a meal from scratch or to buy a ready meal? What difference does the number of people you're cooking for make?

Decimal Time

Stage: 3 Challenge Level:

This problem is designed to intrigue a little. To tackle the
problem, pupils will need to be comfortable with manipulating
fractions and decimals, and it would be a good idea to have
calculators to hand.

It is an excellent way to highlight misconceptions associated with
our digital clock, for example that 12.50 is not 0.5 hours after
12.00. It could be a good vehicle for investigating why our clock
is based on the number 60 and researching calendar systems of
ancient cultures.

The NRICH Project aims to enrich the mathematical experiences of all learners. To support this aim, members of the
NRICH team work in a wide range of capacities, including providing professional development for teachers wishing to
embed rich mathematical tasks into everyday classroom practice. More information on many of our other activities
can be found here.